Self-cleaning lint filter for a recirculating clothes washer

ABSTRACT

A self-cleaning lint filter for a domestic clothes washer is connected between a water container and a pair of reversible pumps. The lint filter includes a circular filter screen with an off-center hole therein. A nozzle receiving water from the water container projects through the hole. When one pump operates, lint is entrapped on one side of the screen. When the other pump operates, the nozzle due to its off-center location effects a swirling turbulence adjacent the same side of the screen to flush the entrapped lint therefrom. The filter screen is loosely fit to flex back and forth as an aid in dislodging entrapped lint.

United States Patent 91 Menk [451 Apr. 17, 1973 SELF-CLEANING LINT FILTER FOR A RECIRCULATING CLOTHES WASHER [75] Inventor: Melvin A. Menk, Dayton, Ohio [73] Assignee: General Motor Corporation,

Detroit, Mich.

[22] Filed: Dec. 27, 1971 [21] Appl. No.: 211,973

[52] US. Cl. ..68/l8 F, 134/111, 210/356 [51] Int. Cl. ..D06f 39/10, BOld 35/22 [58] Field of Search ..210/l67, 106, 108,

[56] References Cited UNITED STATES PATENTS I 3,491,780 1/1970 Kaldenberg ..134/1 1 l X FOREIGN PATENTS OR APPLICATIONS 1,191,781 4/1965 Germany ..68/18 F Pn'mary Examinerl..eon G. Machlin Attomey-Williarn S. Pettigrew et al.

[ ABSTRACT A self-cleaning lint filter for a domestic clothes washer is connected between a water container and a pair of reversible pumps. The lint filter includes a circular filter screen with an off-center hole therein. A nozzle receiving water from the water container projects through the hole. When one pump operates, lint is entrapped on one side of the screen. When the other pump operates, thenozzle due to its off-center location effects a swirling turbulence adjacent the same side of the screen to flush the entrapped lint therefrom. The filter screen is loosely fit to flex back and forth as an aid in dislodging entrapped lint.

5 Claims, 3 Drawing Figures PATENTED APR 1 7 I975 BY %Wr ATTORNEY SELF-CLEANING LINT FILTER FOR A RECIRCULATING CLOTHES WASHER This invention relates to a recirculating type domestic clothes washer and, more particularly, to an improved self-cleaning lint filter therefor.

Many automatic clothes washers with a recirculating system have a filter of some sort beneath the outlet of the recirculating water hose. This outlet is positioned above the tub to catch visible water borne particles such as lint resulting from the wash action and carried in the wash water from the garments being washed. Although a lint filter is a common feature on domestic clothes washers, there have been certain disadvantages with the prior art devices. For instance, lint filters frequently take up space in the access area for loading clothes; some must even be removed before clothes can be loaded; and some are removable for cleaning by the user usually after each wash load to assure continued filtering efficiency. If removable and customerhandled, there is always the chance that the filter will be misplaced or broken. In most prior art filters, only the larger and more obvious foreign matter and lint is trapped in order to resist premature clogging. Moreover, prior art washersare designed to function satisfactorily even if the filter is clogged by providing an overflow into the tub.

A preferred lint filter is one that is concealed, efficientand automatically cleans itself during the clothes washing cycle. Prior art systems with this aim have used the following principle. Lint is entrapped by pumping the recirculating water in one direction over the filter and then pumping the drain water in the reverse direction to flush the entrapped lint to drain. But such prior art systems require at least one check valve in the water handling system and a reversing damper to change pumping direction. Thus, the filter must entrap lint in one flow direction and release it in the other an arrangement which tends to limit filter efficiency. And a check valve is an undesirable restriction in the drain line. This invention is directed to a more efficient and, therefore, improved self-cleaning lint filter which overcomes these and other disadvantages.

Accordingly, it is an object of this invention to provide in a domestic clothes washer a lint filter of improved efficiency utilizing a fine mesh fabric screen and in which the water flow through the screen is not reversed for self-cleaning.

- Another object of this invention is the provision of a self-cleaning lint filter in a domestic clothes washer which requires no auxiliary controls nor check valves in the recirculation and drain systems.

More particularly, an object of this invention is the provision of a self-cleaning lint filter which includes a loosely fitting fabric screen to entrap lint on one side thereof during recirculation and a nozzle on the same side thereof for inducing a swirling turbulence against said one side for removing entrapped lint during drain.

It is also an object of this invention to incorporate the structure last described into a plastic sump attachable to the bottom of a water container and in which the nozzle is integrally formed therewith and adapted thereby to extend through the fabric screen offset from the center thereof to connect said water container to said one side thereof.

Further objects and advantages of the present invention will be apparent from the following description,

reference being had to the accompanying drawings wherein a preferred embodiment of i the present invention is clearly shown.

In the drawings:

FIG. 1 is a schematic front elevational view of a domestic clothes washer with parts broken away to show the self-cleaning lint filter of this invention;

FIG. 2 is a side sectional view partly in elevation of the self-cleaning lint filter; and

FIG. 3 is a' sectional view taken along line 3-3 in FIG. 2.

With reference now to FIG. 1, the environment of this invention in a domestic clothes washer will now be described. The clothes washer includes a cabinet 12 enclosing a tub assembly 14 and a timer 17 for controlling an automatic clothes washing cycle. The tub assembly includes an imperforate outer water container 16 and a perforate spin basket 18 therein. An agitator 20 is disposed within the spin basket 18 for agitating the clothes during a clothes washing cycle.

The tub assembly '14 is mounted on a suspension system shown generally at 22 and more fully taught in U. S. Pat. No. 3,493,118 granted Feb. 3, 1970. The

agitator 20 and the spin basket 18 are connected to a drive mechanism shown generally at 24. The drive mechanism may be of a roller drive type taught more fully in U. S. Pat. No. 3,087,321 granted Apr. 30, 1963. In general, mechanism 24 may be operated in one manner to vertically reciprocate or oscillate the agitator 20 for washing clothes in the tub assembly. When the mechanism is operated in another manner, the spin basket 18 is rotated with respect to the water container 16 for centrifuging water fromthe clothes in the spin basket. i

The water recirculation system will now be described. The water container 16 includes a bottom outlet and an open top 32. A recirculating pump 36 withdraws washing water or liquid from the water container 16 through the bottom outlet 30 and by means of recirculating conduits or hoses 40 and 42 returns the washing liquid to the water container. The purpose of recirculation is to remove lint and other sediment from the recirculating washing liquid. For this purpose, a self-cleaning lint filter is included and shown generally at 50.

The drain system for the clothes washer includes a drain pump 52 for pumping washing liquid from the water container 16 through its bottom outlet 30 and by means of drain conduits or hoses 54 and 56 to a remote drain. Lint filtered from the washing liquid during the recirculation portion of an automatic wash cycle is flushed from the self-cleaning lint filter and pumped to drain by drain pump 52 during the drain portion.

Both the recirculation pump 36 and the drain pump 52 are on a common reversible power shaft 60 which is driven by a belt takeoff from the drive mechanism 24. When the drive mechanism is operating in a manner to reciprocate the agitator 20, the power shaft 60 is rotated in a direction to cause the recirculation pump 36 to recirculate washing liquid. When the drive mechanism 24 is operating in a manner to rotate the spin basket in a centrifuging operation, the power shaft 60 is reversed to cause the drain pump 52 to pump the washing liquid to drain.

Turning now to FIG. 2, the self-cleaning lint filter 50 is comprised of a plastic filter housing 70 having an upper filter sump portion 72 and a lower filter sump portion 74 joined along a peripheral jointure 76 by spin welding or other suitable connecting and sealing arrangement. The housing defines rather a drum-shaped chamber substantially 8 inches in diameter within circular top and bottom walls 69, 71 and cylindrical peripheral wall 73. Positioned within the housing 70 and located by an annular recess inside the peripheral jointure is a filter screen assembly 80 in generally parallel spaced relationship between the top and bottom walls of the filter housing. The upper sump portion 72 may include a pressure bell 82 and nipple 84 for connection witha liquid level control (not shown) to regulate the level of liquid in the water container 16. The upper sump portion 72 includes an open top 85 which connects to the bottom outlet 30 of the water container an annular channel 88 serving to locate a seal to prevent leakage at this connection. A hose fitting 90 on the upper filter sump portion 72 defines a recirculating supply port adapted for connection withrecirculation hose 40. The lower filter sump portion 74 includes a button trap portion 92 and a hose fitting 94 defining a drain port 96 adapted for connection with drain hose 54. Housing 72 may be formed of polypropylene having a wall thickness of substantially 0.060 inch or other suitableplastic material.

The filter screen assembly 80 is comprised of a circular or hoop-like frame 100 of polypropylene material about 0.22 inch wide which frames and. retains a polyester fabric screen 102 of 68X 72 mesh. The fabric screen surrounds a collar 104 offset from the diametric center of the filter screen assembly by 0.500 inch. The inside diameter of collar 104 is 1.020 inches and the outside diameter of the filter screen assembly is 7.660

' inches. The frame 100 of the filter screen assembly includes a notch 106 for properly orienting the filter screen with respect to the housing 70. The fabric screen 102 is sufficiently loosely retained within the frame 100 that a 0.24 inch maximum sag occurs for a purpose to be described hereinafter.

The self-cleaning filter 50 of this invention entraps lint on one side of a filter screen and flushes the entrapped lint therefrom by a swirlingly turbulent flushing action on the same side of the screen instead of backwashing through the screen. For this purpose, the upper filter sump portion 72 includes a nozzle 110 which projects through the screen collar 104 in snug fit relationship therewith at 105. The nozzle 110 includes an opening 112 facing with respect to the lower filter sump portion 74 and the drain connection 94 in a manner to effect a swirlingly turbulent flushing of the underside of the screen 102 when liquid is being pumped from an inlet port 86 in the top wall of the housing to the drain port 96.

The sag built into the filter screen assembly 80 permits movement of the fabric screen from a bowed condition in the direction of the recirculation supply fitting 90 during recirculation to an oppositely bowed and fluttering condition during drain. The flexing of the fabric screen aids in dislodging entrapped lint from the filter screen.

' In operation, a washing cycle may be controlled by the timer 17 to operate a clothes washing cycle. Water is supplied to the water container 16 and spin basket 18. The drive mechanism 24 is energized to reciprocate the agitator 20 in the wash portion of the cycle while rotating the power shaft 60 tooperate the recirculation pump 36. Washing liquid is recirculated from the bottom outlet 30 of the water container and returned by means of the recirculation hose 42 to the water container. As this washing liquid passes through the selfcleaning filter 50, lint and other sediment is deposited on the bottom side of the filter screen 102. During the time that lint is being collected or entrapped, the fabric screen is bowed upwardly (position A).

After agitation and during the drain portion of the cycle, the drive mechanism 24 is adapted to rotate the spin basket 18 and reverse the rotation of the pump power shaft 60. This causes the drain pump 52 to withdraw washing liquid from the bottom outlet 30 of the water container 16 through the lint filter. The orientation of nozzle with respect to the lower filter sump 74 induces a swirling turbulence along the underside of the filter screen. The filter screen now sags downwardly (position B), occasionally fluttering, since the suction thereon is from the drain port 96. The swirling turbulence of the water being pumped todrain together with the flexing of the filter screen tends to dislodge the entrapped lint for entrainment in the washing liquid being pumped todrain.

Lint is caught and removed at least twice during a wash cycle, once during the. wash portion of the cycle and again during the rinse portion of the cycle- The screen area may be increased to handle larger quantities of lint.

While the embodiment of the present invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted.

What is claimed is:

1. In an automatic clothes washing machine having an imperforate tub with top inlet and bottom outlet, a first pump associated with said inlet and said outlet and operable for recirculating liquid to said tub, and a second pump associated with said outlet and operable for pumping liquid from said tub to a drain, the improvement comprising a self-cleaning vfilter assembly a circular generally planar lint filter mounted in said,

chamber in generally parallel spaced relationship between said first and second circular wall means and substantially coextensive therewith, said lint filter having a screen portion in liquid flow intercepting relationship between said inlet port and said recirculation supply port to form a lint entrapping filter,

means forming an upper sump connecting the bottom outlet of said tub to said inlet port and having an outlet nozzle extending through said screen portion in snug fit relation therewith to supply liquid to one side of said screen portion for entrapping lint on said one side when said first pump is operating to recirculate liquid from said inlet port to said recirculation supply port and for cleaning entrapped lint from said one side when said second pump is operating to pump liquid from said inlet port to drain, said outlet nozzle being offset from the radial center of said peripheral wall means toward said drain port on said one side of said screen portion and aimed toward said radial center to induce a swirl in said liquid adjacent said one side returning to said drain port for flushing said entrapped lint therefrom, the lint flushed by the liquid swirl being thereafter pumped by said second pump to drain along with said liquid,

first conduit means connecting the recirculation supply port to the inlet of said first pump to draw liquid from said inlet port to said recirculation Supply port,

second conduit means connecting said drain port to the inlet of said second pump to pump liquid from said inlet port to drain,

and means for operating selectively said first and second pumps.

2. The self-cleaning filter assembly of claim 1 wherein the diameter of said drum-shaped chamber is substantially 8 inches and said ofiset is one-half inch.

3. The self-cleaning filter assembly of claim 2 wherein said screen portion is polyester fabric of 68 X 72 mesh.

4. The self-cleaning filter assembly of claim 1 wherein said housing and said means forming an upper sump are plastic formed in two'pieces joined along a plane which includes said lint filter.

5. In an automatic clothes washing machine having an imperforate tub with top inlet and bottom outlet, a first pump associated with said inlet and said outlet and operable for recirculating liquid to said tub, and a second pump associated with said outlet and operable for pumping liquid from said tub to a drain, the improvement comprising a self-cleaning filter assembly for removing solid contaminants from the recirculating liquid comprising a housing having first and second circular wall means spaced by peripheral wall means to form a drumshaped chamber therebetween;

said drum-shaped chamber having an inlet port, a

drain port and a recirculation supply port thereto,

a circular generally planar lint filter disc mounted in means forming an upper sump connecting the bottom outlet of said tub to said inlet port and having an outlet nozzle extending throughsaid mesh portion in snug fit relation therewith to supply liquid to one side of said mesh portion for entrapping lint on said one side when said first pump is operating to recirculate liquid from said inlet port to said recirculation supply port and for cleaning entrapped lint from said one side when said second pump is operating to pump liquid from said inlet port to drain, said outlet nozzle being arranged with respect to said peripheral wall means and said mesh portion to induce a swirl in said liquid adacent said one side for flushing said entrapped lint therefrom,

first conduit means connecting the recirculation supply port to the inlet of said first pump to draw liquid from said inlet port to said recirculation pp y p second conduit means connecting said drain port to the inlet of said second pump to pump liquid from said inlet port to drain,

means including play, in the fabric mesh portion of said lint filter disc responsive to liquid movement 1 and means for operating selectively said first and second pumps. 

1. In an automatic clothes washing machine having an imperforate tub with top inlet and bottom outlet, a first pump associated with said inlet and said outlet and operable for recirculating liquid to said tub, and a second pump associated with said outlet and operable for pumping liquid from said tub to a drain, the improvement comprising a self-cleaning filter assembly for removing solid contaminants from the recirculating liquid comprising a housing having first and second circular wall means spaced by peripheral wall means to form a drum-shaped chamber therebetween; said drum-shaped chamber having an inlet port, a drain port and a recirculation supply port thereto, a circular generally planar lint filter mounted in said chamber in generally parallel spaced relationship between said first and second circular wall means and substantially coextensive therewith, said lint filter having a screen portion in liquid flow intercepting relationship between said inlet port and said recirculation supply port to form a lint entrapping filter, means forming an upper sump connecting the bottom outlet of said tub to said inlet port and having an outlet nozzle extending through said screen portion in snug fit relation therewith to supply liquid to one side of said screen portion for entrapping lint on said one side when said first pump is operating to recirculate liquid from said inlet port to said recirculation supply port and for cleaning entrapped lint from said one side when said second pump is operating to pump liquid from said inlet port to drain, said outlet nozzle being offset from the radial center of said peripheral wall means toward said drain port on said one side of said screen portion and aimed toward said radial center to induce a swirl in said liquid adjacent said one side returning to said drain port for flushing said entrapped lint therefrom, the lint flushed by the liquid swirl being thereafter pumped by said second pump to drain along with said liquid, first conduit means connecting the recirculation supply port to the inlet of said first pump to draw liquid from said inlet port to said recirculation supply port, second conduit means connecting said drain port to the inlet of said second pump to pump liquid from said inlet port to drain, and means for operating selectively said first and second pumps.
 2. The self-cleaning filter assembly of claim 1 wherein the diameter of said drum-shaped chamber is substantially 8 inches and said offset is one-half inch.
 3. The self-cleaning filter assembly of claim 2 wherein said screen portion is polyester fabric of 68 X 72 mesh.
 4. The self-cleaning filter assembly of claim 1 wherein said housing and said means forming an upper sump are plastic formed in two pieces joined along a plane which includes said lint filter.
 5. In an automatic clothes washing machine having an imperforate tub with top inlet and bottom outlet, a first pump assOciated with said inlet and said outlet and operable for recirculating liquid to said tub, and a second pump associated with said outlet and operable for pumping liquid from said tub to a drain, the improvement comprising a self-cleaning filter assembly for removing solid contaminants from the recirculating liquid comprising a housing having first and second circular wall means spaced by peripheral wall means to form a drum-shaped chamber therebetween; said drum-shaped chamber having an inlet port, a drain port and a recirculation supply port thereto, a circular generally planar lint filter disc mounted in said chamber in generally parallel spaced relationship between said first and second circular wall means, said lint filter disc having a fabric mesh portion in liquid flow intercepting relationship between said inlet port and said recirculation supply port to form a lint entrapping filter, means forming an upper sump connecting the bottom outlet of said tub to said inlet port and having an outlet nozzle extending through said mesh portion in snug fit relation therewith to supply liquid to one side of said mesh portion for entrapping lint on said one side when said first pump is operating to recirculate liquid from said inlet port to said recirculation supply port and for cleaning entrapped lint from said one side when said second pump is operating to pump liquid from said inlet port to drain, said outlet nozzle being arranged with respect to said peripheral wall means and said mesh portion to induce a swirl in said liquid adjacent said one side for flushing said entrapped lint therefrom, first conduit means connecting the recirculation supply port to the inlet of said first pump to draw liquid from said inlet port to said recirculation supply port, second conduit means connecting said drain port to the inlet of said second pump to pump liquid from said inlet port to drain, means including play in the fabric mesh portion of said lint filter disc responsive to liquid movement in said housing when said first or second pump is operating to flex said mesh portion respectively in opposite directions for dislodging the entrapped lint therefrom, the lint dislodged by the flexing of said mesh portion upon operation of said second pump together with the lint flushed by the liquid swirl being thereafter pumped by said second pump to drain along with said liquid, and means for operating selectively said first and second pumps. 